Synthesis and mechanical properties of novel Ti-(SiCf/Al3Ti) ceramic-fiber-reinforced metal-intermetallic-laminated (CFR-MIL) composites

The innovative Ti-(SiCf/Al3Ti) ceramic-fiber-reinforced metal-intermetallic-laminated (CFR-MIL) composites were successfully fabricated by vacuum hot pressing using titanium foils, aluminum foils and SiC ceramic fibers. The synthesized Ti-(SiCf/Al3Ti) composite showed a unique multilayered microstructure consisting of alternating SiCf/Al3Ti composite layers (SiC fiber as reinforcement) and Ti layers. In addition, reaction annealing technique was employed to improve the interfacial performance of SiC fiber with Al3Ti matrix. The microstructure evolution of the laminated composite during hot-pressing and annealing was experimentally characterized using scanning electron microscopy and energy dispersive spectroscopy. The formation mechanism of micro-laminated structure was discussed. Furthermore, the mechanical properties of the Ti-(SiCf/Al3Ti) laminated composite and its components were investigated by tensile and nanoindentation tests. The results indicated that Ti-(SiCf/Al3Ti) laminated composite exhibited superior mechanical properties compared to Ti-Al3Ti, which was likely attributed to the introduction of SiC fiber. The failure mechanism of CFR-MIL composite was the combined fracture behaviors of ductile fracture of Ti, brittle fracture of Al3Ti and fiber debonding, pullout and breakage of SiC.